How to Install a Drain Pipe in a Bath Tub

The drain pipe that runs in a tub is attached to the overflow pipe running vertically along the same side of the faucet tub. When installing the drain pipe, you must also install the overflow pipe, as both pipes connect and drain into the main drain pipe below.

If your home has an unfinished basement below the bathtub or a wall-mounted access panel directly behind the bathtub, tubes can be easily accessed. Otherwise you will need to create an access panel.


  1. Tighten the connections between the drain tube, tube overflow and the t both tubes connect. Use your hands to tighten the connections.
  2. Open door tub access on the wall directly behind the faucet, or access the tub from the basement area just below the bath. Place the drain assembly in place and use a pencil to mark any portion of the pipe that is too long for the fitting to connect to the main drain pipe under the bath.
  3. Practical at the end of the tub drain pipe assembly with a metal saw. Apply silicone caulking to one side of the rubber gaskets that came with the Assembly, then press over the holes in the overflow tube and drain pipe.
  4. Place the drain assembly back into place under the tub and tighten the connection between the bottom of the Assembly and the main drain pipe until it is hand tight. Position the overflow cover over overflow drain the tub, then drive the screws through the cover and into the screw holes in the overflow tube.
  5. Screw the bathtub drain into the opening in the drain pipe. Take the side of the drainage work or grids with a pair of pliers and turn the drain part until it is tight.